1. Field of the Invention
The present invention relates generally to radio pagers, and more particularly to a power saving radio pager adapted to receive paging signals of variable coding format.
2. Description of the Related Art
A paging system, known as the FLEX system, provides variable format transmissions in which either binary-coded or quaternary-coded signals of variable rate are encapsulated in the payload field of a frame. Pagers of this system include A/D conversion and symbol decision circuitry necessary for detecting a quaternary-coded signal and waveshaping circuitry for detecting a binary-coded signal. The latter is used as an input of a synchronizer to provide a symbol timing pulse to the A/D conversion and symbol decision circuitry. The detected quaternary- or binary-coded signal is then entered to a decoder. The output of the decoder is then searched for a match with the user's address for alerting the user.
Since the output of the A/D conversion and symbol decision circuitry is useless when the signal in the payload field is a binary-coded signal, a need exists for saving power during such times.